S10 A/C question

1996 S10 pickup 4.3L engine. Last year the A/C would occasionally cut out. Wait a minute and it would again blow cool air. Didn't think much of it until this year, when the A/C is dead 100% of the time. It appears that the A/C clutch is not kicking in. I have checked : the relay (good) and the A/C request input signal to the VCM (good). Removing the relay and jumpering the contacts causes clutch to activate (power is on). My question has to do with something called the compresser delay relay. Where does it enter the picture? My service manual mentions it but I cannot find it on the wiring diagram. Does it fit somewhere between the VCM A/C output and the Clutch relay? I am down to 3 choices: the VCM A/C output is dead, the wire from the VCM A/C output to the clutch relay is open, or the Compressor delay relay is screwing things up. I can check the first 2 but how do I check the delay relay?